Allow null operators for result and using Result as return type with enabled InlineClasses

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/checkers/ResultTypeWithNullableOperatorsChecker.kt

@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.resolve.calls.checkers
 
 import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.diagnostics.reportDiagnosticOnce
 import org.jetbrains.kotlin.lexer.KtTokens
@@ -16,6 +17,8 @@ import org.jetbrains.kotlin.types.expressions.ControlStructureTypingUtils
 
 class ResultTypeWithNullableOperatorsChecker : CallChecker {
     override fun check(resolvedCall: ResolvedCall<*>, reportOn: PsiElement, context: CallCheckerContext) {
+        if (context.languageVersionSettings.supportsFeature(LanguageFeature.AllowNullOperatorsForResult)) return
+
         val name = resolvedCall.resultingDescriptor.name
         val operationNode = resolvedCall.call.callOperationNode
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ResultClassInReturnTypeChecker.kt

@@ -6,6 +6,8 @@
 package org.jetbrains.kotlin.resolve.checkers
 
 import org.jetbrains.kotlin.config.AnalysisFlags
+import org.jetbrains.kotlin.config.LanguageFeature
+import org.jetbrains.kotlin.config.LanguageVersion
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.diagnostics.reportDiagnosticOnce
@@ -17,7 +19,12 @@ import org.jetbrains.kotlin.types.KotlinType
 
 class ResultClassInReturnTypeChecker : DeclarationChecker {
     override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, context: DeclarationCheckerContext) {
-        if (context.languageVersionSettings.getFlag(AnalysisFlags.allowResultReturnType)) return
+        val languageVersionSettings = context.languageVersionSettings
+        if (
+            languageVersionSettings.getFlag(AnalysisFlags.allowResultReturnType) ||
+            languageVersionSettings.supportsFeature(LanguageFeature.InlineClasses) &&
+            languageVersionSettings.supportsFeature(LanguageFeature.AllowResultInReturnType)
+        ) return
 
         if (declaration !is KtCallableDeclaration || descriptor !is CallableMemberDescriptor) return
 

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_3.kt

@@ -0,0 +1,7 @@
+// !LANGUAGE: -AllowNullOperatorsForResult
+// !DIAGNOSTICS: -UNUSED_EXPRESSION
+
+fun test(r: Result<Int>?) {
+    r <!RESULT_CLASS_WITH_NULLABLE_OPERATOR!>?:<!> 0
+    r<!RESULT_CLASS_WITH_NULLABLE_OPERATOR!>?.<!>isFailure
+}

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_3.txt

@@ -0,0 +1,3 @@
+package
+
+public fun test(/*0*/ r: kotlin.Result<kotlin.Int>?): kotlin.Unit

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_4.kt

@@ -0,0 +1,7 @@
+// !LANGUAGE: +AllowNullOperatorsForResult
+// !DIAGNOSTICS: -UNUSED_EXPRESSION
+
+fun test(r: Result<Int>?) {
+    r ?: 0
+    r?.isFailure
+}

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_4.txt

@@ -0,0 +1,3 @@
+package
+
+public fun test(/*0*/ r: kotlin.Result<kotlin.Int>?): kotlin.Unit

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnTypeWithFlag.kt

@@ -1,4 +1,5 @@
 // !ALLOW_RESULT_RETURN_TYPE
+// !LANGUAGE: -AllowNullOperatorsForResult
 
 fun result(): Result<Int> = TODO()
 val resultP: Result<Int> = result()

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_3.kt

@@ -0,0 +1,4 @@
+// !LANGUAGE: +InlineClasses -AllowResultInReturnType
+
+fun result(): <!RESULT_CLASS_IN_RETURN_TYPE!>Result<Int><!> = TODO()
+val resultP: <!RESULT_CLASS_IN_RETURN_TYPE!>Result<Int><!> = result()

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_3.txt

@@ -0,0 +1,4 @@
+package
+
+public val resultP: kotlin.Result<kotlin.Int>
+public fun result(): kotlin.Result<kotlin.Int>

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_4.kt

@@ -0,0 +1,4 @@
+// !LANGUAGE: +InlineClasses +AllowResultInReturnType
+
+fun result(): Result<Int> = TODO()
+val resultP: Result<Int> = result()

compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_4.txt

@@ -0,0 +1,4 @@
+package
+
+public val resultP: kotlin.Result<kotlin.Int>
+public fun result(): kotlin.Result<kotlin.Int>

compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeInReturnType.kt

@@ -1,5 +1,5 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER, -UNUSED_EXPRESSION, -UNUSED_VARIABLE
-// !LANGUAGE: +InlineClasses
+// !LANGUAGE: +InlineClasses -AllowResultInReturnType
 
 typealias ResultAlias<T> = Result<T>
 

compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeInReturnType_1_4.kt

@@ -0,0 +1,124 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER, -UNUSED_EXPRESSION, -UNUSED_VARIABLE
+// !LANGUAGE: +InlineClasses +AllowResultInReturnType
+
+typealias ResultAlias<T> = Result<T>
+
+inline class InlineResult<out T>(private val r: Result<T>)
+
+fun params(
+    r1: Result<Int>,
+    r2: Result<Int>?,
+    r3: ResultAlias<String>,
+    r4: List<Result<Int>>,
+    r5: InlineResult<Int>,
+    <!FORBIDDEN_VARARG_PARAMETER_TYPE!>vararg<!> r6: Result<Int>
+) {}
+
+class CtorParams(r1: Result<Int>)
+
+fun returnTypePublic(): Result<Int> = TODO()
+internal fun returnTypeInternal(): Result<Int> = TODO()
+private fun returnTypePrivate(): Result<Int> = TODO()
+fun returnTypeNullable(): Result<Int>? = TODO()
+fun returnTypeAlias(): ResultAlias<Int> = TODO()
+fun returnInferred(r1: Result<Int>, r2: ResultAlias<Int>, b: Boolean) = if (b) r1 else r2
+
+fun returnTypeInline(): InlineResult<Int> = TODO()
+fun returnContainer(): List<Result<Int>> = TODO()
+
+val topLevelP: Result<Int> = TODO()
+val topLevelPInferred = topLevelP
+internal val topLevelPInternal: Result<Int> = TODO()
+
+private val topLevelPPrivate: Result<Int> = TODO()
+private val topLevelPPrivateInferred = topLevelP
+
+private val topLevelPPrivateCustomGetter: Result<Int>
+    get() = TODO()
+
+val asFunctional: () -> Result<Int> = TODO()
+
+open class PublicCls(
+    val r1: Result<String>,
+    val r2: Result<Int>?,
+    val r3: ResultAlias<Int>,
+    val r4: ResultAlias<Int>?,
+
+    val r5: InlineResult<Int>,
+
+    internal val r6: Result<Int>,
+
+    private val r7: Result<Int>,
+    val r8: List<Result<Int>>
+) {
+    val p1: Result<Int> = TODO()
+    var p2: Result<Int> = TODO()
+    val p3: ResultAlias<Int>? = TODO()
+
+    val p4 = p1
+
+    internal val p5: Result<Int> = TODO()
+
+    private var p6: Result<Int> = TODO()
+
+    internal val p7 = p1
+    protected val p8 = p1
+
+    fun returnInCls(): Result<Int> = TODO()
+    protected fun returnInClsProtected(): Result<Int> = TODO()
+    private fun returnInClsPrivate(): Result<Int> = TODO()
+}
+
+internal open class InternalCls(
+    val r1: Result<Int>,
+    val r2: ResultAlias<Int>?,
+
+    val r3: List<Result<Int>>
+) {
+    companion object {
+        val cr1: Result<Int> = TODO()
+
+        private val cr2: Result<Int> = TODO()
+    }
+
+    val p1 = r1
+    val p2: Result<String> = TODO()
+
+    protected val p3 = p1
+
+    fun returnInInternal(): Result<Int> = TODO()
+    protected fun returnInClsProtected(): Result<Int> = TODO()
+}
+
+private class PrivateCls(
+    val r1: Result<Int>,
+    val r2: ResultAlias<Int>?,
+    val r3: List<Result<Int>>
+) {
+    companion object {
+        val cr1: Result<Int> = TODO()
+        private val cr2: Result<Int> = TODO()
+    }
+
+    val p1 = r1
+    val p2: Result<String> = TODO()
+
+    fun returnInPrivate(): Result<Int> = TODO()
+}
+
+fun local(r: Result<Int>) {
+    val l1: Result<Int>? = null
+    val l2 = r
+
+    fun localFun(): Result<Int> = TODO()
+
+    class F {
+        val p1: Result<Int> = r
+        val p2 = r
+    }
+}
+
+fun <T> resultInGenericFun(r: Result<Int>): T = r <!UNCHECKED_CAST!>as T<!>
+
+val asFunPublic: () -> Result<Int> = TODO()
+private val asFun: () -> Result<Int>? = TODO()

compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeInReturnType_1_4.txt

@@ -0,0 +1,110 @@
+package
+
+private val asFun: () -> kotlin.Result<kotlin.Int>?
+public val asFunPublic: () -> kotlin.Result<kotlin.Int>
+public val asFunctional: () -> kotlin.Result<kotlin.Int>
+public val topLevelP: kotlin.Result<kotlin.Int>
+public val topLevelPInferred: kotlin.Result<kotlin.Int>
+internal val topLevelPInternal: kotlin.Result<kotlin.Int>
+private val topLevelPPrivate: kotlin.Result<kotlin.Int>
+private val topLevelPPrivateCustomGetter: kotlin.Result<kotlin.Int>
+private val topLevelPPrivateInferred: kotlin.Result<kotlin.Int>
+public fun local(/*0*/ r: kotlin.Result<kotlin.Int>): kotlin.Unit
+public fun params(/*0*/ r1: kotlin.Result<kotlin.Int>, /*1*/ r2: kotlin.Result<kotlin.Int>?, /*2*/ r3: ResultAlias<kotlin.String> /* = kotlin.Result<kotlin.String> */, /*3*/ r4: kotlin.collections.List<kotlin.Result<kotlin.Int>>, /*4*/ r5: InlineResult<kotlin.Int>, /*5*/ vararg r6: kotlin.Result<kotlin.Int> /*kotlin.Array<out kotlin.Result<kotlin.Int>>*/): kotlin.Unit
+public fun </*0*/ T> resultInGenericFun(/*0*/ r: kotlin.Result<kotlin.Int>): T
+public fun returnContainer(): kotlin.collections.List<kotlin.Result<kotlin.Int>>
+public fun returnInferred(/*0*/ r1: kotlin.Result<kotlin.Int>, /*1*/ r2: ResultAlias<kotlin.Int> /* = kotlin.Result<kotlin.Int> */, /*2*/ b: kotlin.Boolean): kotlin.Result<kotlin.Int>
+public fun returnTypeAlias(): ResultAlias<kotlin.Int> /* = kotlin.Result<kotlin.Int> */
+public fun returnTypeInline(): InlineResult<kotlin.Int>
+internal fun returnTypeInternal(): kotlin.Result<kotlin.Int>
+public fun returnTypeNullable(): kotlin.Result<kotlin.Int>?
+private fun returnTypePrivate(): kotlin.Result<kotlin.Int>
+public fun returnTypePublic(): kotlin.Result<kotlin.Int>
+
+public final class CtorParams {
+    public constructor CtorParams(/*0*/ r1: kotlin.Result<kotlin.Int>)
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public final inline class InlineResult</*0*/ out T> {
+    public constructor InlineResult</*0*/ out T>(/*0*/ r: kotlin.Result<T>)
+    private final val r: kotlin.Result<T>
+    public open override /*1*/ /*synthesized*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*synthesized*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*synthesized*/ fun toString(): kotlin.String
+}
+
+internal open class InternalCls {
+    public constructor InternalCls(/*0*/ r1: kotlin.Result<kotlin.Int>, /*1*/ r2: ResultAlias<kotlin.Int>? /* = kotlin.Result<kotlin.Int>? */, /*2*/ r3: kotlin.collections.List<kotlin.Result<kotlin.Int>>)
+    public final val p1: kotlin.Result<kotlin.Int>
+    public final val p2: kotlin.Result<kotlin.String>
+    protected final val p3: kotlin.Result<kotlin.Int>
+    public final val r1: kotlin.Result<kotlin.Int>
+    public final val r2: ResultAlias<kotlin.Int>? /* = kotlin.Result<kotlin.Int>? */
+    public final val r3: kotlin.collections.List<kotlin.Result<kotlin.Int>>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    protected final fun returnInClsProtected(): kotlin.Result<kotlin.Int>
+    public final fun returnInInternal(): kotlin.Result<kotlin.Int>
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public companion object Companion {
+        private constructor Companion()
+        public final val cr1: kotlin.Result<kotlin.Int>
+        private final val cr2: kotlin.Result<kotlin.Int>
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}
+
+private final class PrivateCls {
+    public constructor PrivateCls(/*0*/ r1: kotlin.Result<kotlin.Int>, /*1*/ r2: ResultAlias<kotlin.Int>? /* = kotlin.Result<kotlin.Int>? */, /*2*/ r3: kotlin.collections.List<kotlin.Result<kotlin.Int>>)
+    public final val p1: kotlin.Result<kotlin.Int>
+    public final val p2: kotlin.Result<kotlin.String>
+    public final val r1: kotlin.Result<kotlin.Int>
+    public final val r2: ResultAlias<kotlin.Int>? /* = kotlin.Result<kotlin.Int>? */
+    public final val r3: kotlin.collections.List<kotlin.Result<kotlin.Int>>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final fun returnInPrivate(): kotlin.Result<kotlin.Int>
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+    public companion object Companion {
+        private constructor Companion()
+        public final val cr1: kotlin.Result<kotlin.Int>
+        private final val cr2: kotlin.Result<kotlin.Int>
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}
+
+public open class PublicCls {
+    public constructor PublicCls(/*0*/ r1: kotlin.Result<kotlin.String>, /*1*/ r2: kotlin.Result<kotlin.Int>?, /*2*/ r3: ResultAlias<kotlin.Int> /* = kotlin.Result<kotlin.Int> */, /*3*/ r4: ResultAlias<kotlin.Int>? /* = kotlin.Result<kotlin.Int>? */, /*4*/ r5: InlineResult<kotlin.Int>, /*5*/ r6: kotlin.Result<kotlin.Int>, /*6*/ r7: kotlin.Result<kotlin.Int>, /*7*/ r8: kotlin.collections.List<kotlin.Result<kotlin.Int>>)
+    public final val p1: kotlin.Result<kotlin.Int>
+    public final var p2: kotlin.Result<kotlin.Int>
+    public final val p3: ResultAlias<kotlin.Int>? /* = kotlin.Result<kotlin.Int>? */
+    public final val p4: kotlin.Result<kotlin.Int>
+    internal final val p5: kotlin.Result<kotlin.Int>
+    private final var p6: kotlin.Result<kotlin.Int>
+    internal final val p7: kotlin.Result<kotlin.Int>
+    protected final val p8: kotlin.Result<kotlin.Int>
+    public final val r1: kotlin.Result<kotlin.String>
+    public final val r2: kotlin.Result<kotlin.Int>?
+    public final val r3: ResultAlias<kotlin.Int> /* = kotlin.Result<kotlin.Int> */
+    public final val r4: ResultAlias<kotlin.Int>? /* = kotlin.Result<kotlin.Int>? */
+    public final val r5: InlineResult<kotlin.Int>
+    internal final val r6: kotlin.Result<kotlin.Int>
+    private final val r7: kotlin.Result<kotlin.Int>
+    public final val r8: kotlin.collections.List<kotlin.Result<kotlin.Int>>
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public final fun returnInCls(): kotlin.Result<kotlin.Int>
+    private final fun returnInClsPrivate(): kotlin.Result<kotlin.Int>
+    protected final fun returnInClsProtected(): kotlin.Result<kotlin.Int>
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+public typealias ResultAlias</*0*/ T> = kotlin.Result<T>

compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeWithNullableOperators.kt

@@ -1,4 +1,5 @@
 // !DIAGNOSTICS: -UNUSED_EXPRESSION
+// !LANGUAGE: -AllowNullOperatorsForResult -AllowResultInReturnType
 
 fun <T> id(x: T): T = x
 

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestWithStdLibGenerated.java

@@ -1513,11 +1513,31 @@ public class DiagnosticsTestWithStdLibGenerated extends AbstractDiagnosticsTestW
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/coroutines"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
         }
 
+        @TestMetadata("allowNullOperatorsForResult_1_3.kt")
+        public void testAllowNullOperatorsForResult_1_3() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_3.kt");
+        }
+
+        @TestMetadata("allowNullOperatorsForResult_1_4.kt")
+        public void testAllowNullOperatorsForResult_1_4() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_4.kt");
+        }
+
         @TestMetadata("allowResultInReturnTypeWithFlag.kt")
         public void testAllowResultInReturnTypeWithFlag() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnTypeWithFlag.kt");
         }
 
+        @TestMetadata("allowResultInReturnType_1_3.kt")
+        public void testAllowResultInReturnType_1_3() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_3.kt");
+        }
+
+        @TestMetadata("allowResultInReturnType_1_4.kt")
+        public void testAllowResultInReturnType_1_4() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_4.kt");
+        }
+
         @TestMetadata("callableReferences.kt")
         public void testCallableReferences() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/callableReferences.kt");
@@ -1763,6 +1783,11 @@ public class DiagnosticsTestWithStdLibGenerated extends AbstractDiagnosticsTestW
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeInReturnType.kt");
         }
 
+        @TestMetadata("usageOfResultTypeInReturnType_1_4.kt")
+        public void testUsageOfResultTypeInReturnType_1_4() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeInReturnType_1_4.kt");
+        }
+
         @TestMetadata("usageOfResultTypeWithNullableOperators.kt")
         public void testUsageOfResultTypeWithNullableOperators() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeWithNullableOperators.kt");

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsTestWithStdLibUsingJavacGenerated.java

@@ -1513,11 +1513,31 @@ public class DiagnosticsTestWithStdLibUsingJavacGenerated extends AbstractDiagno
             KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/testsWithStdLib/coroutines"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
         }
 
+        @TestMetadata("allowNullOperatorsForResult_1_3.kt")
+        public void testAllowNullOperatorsForResult_1_3() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_3.kt");
+        }
+
+        @TestMetadata("allowNullOperatorsForResult_1_4.kt")
+        public void testAllowNullOperatorsForResult_1_4() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowNullOperatorsForResult_1_4.kt");
+        }
+
         @TestMetadata("allowResultInReturnTypeWithFlag.kt")
         public void testAllowResultInReturnTypeWithFlag() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnTypeWithFlag.kt");
         }
 
+        @TestMetadata("allowResultInReturnType_1_3.kt")
+        public void testAllowResultInReturnType_1_3() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_3.kt");
+        }
+
+        @TestMetadata("allowResultInReturnType_1_4.kt")
+        public void testAllowResultInReturnType_1_4() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/allowResultInReturnType_1_4.kt");
+        }
+
         @TestMetadata("callableReferences.kt")
         public void testCallableReferences() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/callableReferences.kt");
@@ -1763,6 +1783,11 @@ public class DiagnosticsTestWithStdLibUsingJavacGenerated extends AbstractDiagno
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeInReturnType.kt");
         }
 
+        @TestMetadata("usageOfResultTypeInReturnType_1_4.kt")
+        public void testUsageOfResultTypeInReturnType_1_4() throws Exception {
+            runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeInReturnType_1_4.kt");
+        }
+
         @TestMetadata("usageOfResultTypeWithNullableOperators.kt")
         public void testUsageOfResultTypeWithNullableOperators() throws Exception {
             runTest("compiler/testData/diagnostics/testsWithStdLib/coroutines/usageOfResultTypeWithNullableOperators.kt");

compiler/util/src/org/jetbrains/kotlin/config/LanguageVersionSettings.kt

@@ -118,6 +118,8 @@ enum class LanguageFeature(
     ProperFinally(KOTLIN_1_4, kind = BUG_FIX),
     ProhibitVarargAsArrayAfterSamArgument(KOTLIN_1_4, kind = BUG_FIX),
     AllowAssigningArrayElementsToVarargsInNamedFormForFunctions(KOTLIN_1_4),
+    AllowNullOperatorsForResult(KOTLIN_1_4),
+    AllowResultInReturnType(KOTLIN_1_4),
 
     ProperVisibilityForCompanionObjectInstanceField(sinceVersion = null, kind = BUG_FIX),
     // Temporarily disabled, see KT-27084/KT-22379